Process for purifying a lipophilic fluid

ABSTRACT

A process for purifying dry cleaning solvents from a mixture containing used dry cleaning solvents and contaminants, such as laundry soils, fabric treating agents.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 60/547,355 filed on Feb. 24, 2004; and U.S. Provisional ApplicationSer. No. 60/483,290 filed on Jun. 27, 2003.

FIELD OF THE INVENTION

The present invention relates to a process for purifying dry cleaningsolvents from a mixture containing used dry cleaning solvents andcontaminants, such as laundry soils, fabric treating agents.

BACKGROUND OF THE INVENTION

Cleaning applications typically involve the removal of foreign matteroff surfaces. In laundry applications, this involves the removal of bothhydrophobic and hydrophilic soils (food stains, blood, grass, dirt,grease, oils, etc.) off various fabrics including cotton, polyester,silk, rayon, wool and various blends of these materials.

For laundry applications, the consumer has two choices for removal ofsoils: conventional water based cleaning and dry cleaning (i.e.,non-aqueous based cleaning). Compositions suitable for use inconventional water based fabric cleaning systems have been optimizedover the years. Specifically, laundry detergents that includesurfactants, enzymes, builders, bleaches, chelants, polymers and otheradditives have been shown to remove both hydrophilic and hydrophobicsoils efficiently in a water based fabric cleaning system. Morespecifically, while cotton, polyester and various blends can beefficiently cleaned using conventional water based systems, other moredelicate fabrics, such as silk, wool, and rayon, are prone to fabricdamages or shrinkages caused by the water based cleaning process andgenerally rely on the dry cleaning process.

The dry cleaning process refers to a process where low or no water isused in the cleaning system; it uses various non-aqueous organicsolvents, such as halocarbons, hydrocarbons, densified carbon dioxide,glycol ethers and silicones.

Conventional detergent compositions and additives are designed for waterbased cleaning. It has been found that those conventional detergentcompositions and additives are not effective fabric cleaning agents indry cleaning solvents due to low compatibility with these solvents.

Some additives, such as detersive surfactants, have been developed fordry cleaning applications. An important design feature of theseadditives is their enhanced compatibility with the dry cleaningsolvents. Not limited in theory, it is believed that these detersivesurfactants can boost detergency by solubilizing the target soils; bysuspending water in the dry cleaning solvents or system, if low levelsof water are utilized; and by forming reverse micelles that helptrapping soils for removal from the fabric treating system. Surfactantdetergency has been discussed in “Detergency of Specialty Surfactants”,by F. E. Friedli, Marcel Dekker, Inc., NY (1988). Use of surfactants ina dry cleaning application has been disclosed in U.S. Pat. No.5,944,996; U.S. Pat. No. 6,548,466; U.S. Pat. No. 6,461,387; U.S. Pat.No. 6,148,644; and U.S. Pat. No. 6,114,295.

Accordingly, there is a continuing need to develop fabric treatingagents to enhance soil removal and other fabric treating benefits innon-aqueous cleaning applications.

It is well known that after being used in a laundering treatment, thedry cleaning solvents typically contain fabric treating agents, such assurfactants, soil release polymers, bleaches, enzymes, and other adjunctingredients. Since the dry cleaning solvents are more expensive thanwater, there is a need to recycle/reuse the dry cleaning solvents inmore than one treatment. Conventional purification process usesdistillation to remove the fabric treating agents from the dry cleaningsolvents. However, equipment and conditions to run a distillation methodare extremely burdensome, energy consuming, and not practical for use ina consumer's home. Accordingly, there is a need to remove fabrictreating agents from dry cleaning solvents without distillation.Representative systems using the distillation method are disclosed in EP543,665 and U.S. Pat. Nos. 5,942,007; 6,056,789; 6,059,845; and6,086,635.

A typical non-distillative purification method employs filter containingclay and/or activated carbons. Representative filters containing carbonand clay adsorbent materials are disclosed in U.S. Pat. Nos. 4,277,336and 3,658,459, and some are commercially available KleenRite® filter.However, such filter has a rather limited lifetime before it has to bereplaced and are less efficient in removing fabric treating agents.

Therefore, there is a need for a method that effectively removes fabrictreating agents, especially surfactants from a dry cleaning solvent sothat the purified solvent can be recycled/reused.

There is also a need to have a method capable of purifying a drycleaning solvent in a safe, economical and energy efficient manner.Therefore, there is a need for a non-distillation method that removesfabric treating agents from the dry cleaning solvent at low temperatureand ambient pressure.

Based on the foregoing, it is desirable to have a method that chemicallymodifies or converts the contaminants into less solublecompounds/molecules, which can be easily removed from the dry cleaningsolvent. It is also desirable to have a method that changes thecharacteristics of the mixture thereby rendering the contaminants lesssoluble in the mixture such that the contaminants can be easilyseparated from the mixture. It is further desirable to have apurification process comprising both methods to further enhance theseparation of the contaminants from the lipophilic solvent.

SUMMARY OF THE INVENTION

The present invention relates to a process for purifying a lipophilicfluid, the process comprising the steps of:

-   -   (a) obtaining a mixture comprising a lipophilic fluid and one or        more contaminants;    -   (b) chemically modifying the contaminant;    -   (c) contacting the mixture with a purification agent, thereby        changing the solubility of the contaminant in the mixture; and    -   (d) separating the contaminant from the lipophilic fluid.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

The term “fabric article” used herein is intended to mean any articlethat is customarily cleaned in a conventional laundry process or in adry cleaning process. As such the term encompasses articles of clothing,linen, drapery, and clothing accessories. The term also encompassesother items made in whole or in part of fabric, such as carpets, totebags, furniture covers, tarpaulins, car interior, and the like.

The term “absorbent material” or “absorbent polymer” as used hereinmeans any material capable of selectively ingesting (i.e., absorbing oradsorbing) water and/or water-containing liquids without ingesting drycleaning solvents. In other words, absorbent materials or absorbentpolymers comprise a water absorbing agent, which is referred to in theart as “gel”, “polymeric gel” and “super absorbent polymers”.

The terms “fabric treatment composition” or “fabric treatingcomposition” as used herein mean a dry cleaning solvent-containingcomposition that comes into direct contact with fabric articles to becleaned. It is understood that the composition may also provide usesother than cleaning, such as conditioning, sizing, and other fabric caretreatments. Thus, it may be used interchangeably with the term “fabriccare composition”. Furthermore, optional cleaning adjuncts (such asadditional detersive surfactants, bleaches, perfumes, and the like) andother fabric care agents may be added to the composition. It isunderstood that the term “fabric treating agent/additive” or “fabriccare agent/additive” encompasses the cleaning adjuncts and the finishingor fabric care additives.

The term “dry cleaning” or “non-aqueous cleaning” as used herein means anon-aqueous fluid is used as the dry cleaning solvent to clean a fabricarticle. However, water can be added to the “dry cleaning” method as anadjunct cleaning agent. The amount of water can comprise up to about 25%by weight of the dry cleaning solvent or the fabric treating compositionin a “dry cleaning” process. The non-aqueous fluid is referred to as the“lipophilic fluid” or “dry cleaning solvent”.

The terms “soil” or ‘laundry soil” as used herein mean any undesirableextraneous substance on a fabric article that is the target for removalby a cleaning process. By the terms “water-based” or “hydrophilic”soils, it is meant that the soil comprised water at the time it firstcame in contact with the fabric article, or the soil retains a certainamount of water on the fabric article. Examples of water-based soilsinclude, but are not limited to beverages, many food soils, watersoluble dyes, bodily fluids such as sweat, urine or blood, outdoor soilssuch as grass stains and mud. On the other hand, the term “lipophilic”soils, as used herein means the soil has high solubility in or affinityfor the lipophilic fluid. Examples of lipophilic soils include, but arenot limited to body soils, such as mono-, di-, and tri-glycerides,saturated and unsaturated fatty acids, non-polar hydrocarbons, waxes andwax esters, lipids; and laundry materials such as nonionic surfactants;and mixtures thereof.

As used herein, the term “insoluble” means that a material willphysically separate (i.e. settle-out, flocculate, float) from the liquidmedium (a dry cleaning solvent or water) within 24 hours after beingadded to the liquid medium, whereas the term “soluble” means that amaterial does not physically separate from the liquid medium within 24hours after addition.

Lipophilic Fluid

“Lipophilic fluid” as used herein means any liquid or mixture of liquidthat is immiscible with water at up to 20% by weight of water. Ingeneral, a suitable lipophilic fluid can be fully liquid at ambienttemperature and pressure, can be an easily melted solid, e.g., one thatbecomes liquid at temperatures in the range from about 0° C. to about60° C., or can comprise a mixture of liquid and vapor phases at ambienttemperatures and pressures, e.g., at 25° C. and 1 atm. pressure.

The suitable lipophilic fluid may be non-flammable or, have relativelyhigh flash points and/or low VOC characteristics, these terms havingconventional meanings as used in the dry cleaning industry, to equal orexceed the characteristics of known conventional dry cleaning fluids. Asused herein, the “dry cleaning solvents” useful in the present inventionrefers to the lipophilic fluids.

Non-limiting examples of suitable lipophilic fluid materials includesiloxanes, other silicones, hydrocarbons, glycol ethers, glycerinederivatives such as glycerine ethers, perfluorinated amines,perfluorinated and hydrofluoroether solvents, low-volatilitynonfluorinated organic solvents, diol solvents, otherenvironmentally-friendly solvents and mixtures thereof.

“Siloxane” as used herein means silicone fluids that are non-polar andinsoluble in water or lower alcohols. Linear siloxanes (see for exampleU.S. Pat. Nos. 5,443,747, and 5,977,040) and cyclic siloxanes are usefulherein, including the cyclic siloxanes selected from the groupconsisting of octamethyl-cyclotetrasiloxane (tetramer),dodecamethyl-cyclohexasiloxane (hexamer), decamethyl-cyclopentasiloxane(pentamer, commonly referred to as “D5”), and mixtures thereof. Asuitable siloxane comprises more than about 50% cyclic siloxanepentamer, or more than about 75% cyclic siloxane pentamer, or at leastabout 90% of the cyclic siloxane pentamer. Also suitable for use hereinare siloxanes that are a mixture of cyclic siloxanes having at leastabout 90% (or at least about 95%) pentamer and less than about 10% (orless than about 5%) tetramer and/or hexamer.

The lipophilic fluid can include any fraction of dry-cleaning solvents,especially newer types including fluorinated solvents, or perfluorinatedamines. Some perfluorinated amines such as perfluorotributylamines,while unsuitable for use as lipophilic fluid, may be present as one ofmany possible adjuncts present in the lipophilic fluid-containingcomposition.

Other suitable lipophilic fluids include, but are not limited to, diolsolvent systems e.g., higher diols such as C₆ or C₈ or higher diols,organosilicone solvents including both cyclic and acyclic types, and thelike, and mixtures thereof.

Non-limiting examples of low volatility non-fluorinated organic solventsinclude for example OLEAN® and other polyol esters, or certainrelatively nonvolatile biodegradable mid-chain branched petroleumfractions.

Non-limiting examples of glycol ethers include propylene glycol methylether, propylene glycol n-propyl ether, propylene glycol t-butyl ether,propylene glycol n-butyl ether, dipropylene glycol methyl ether,dipropylene glycol n-propyl ether, dipropylene glycol t-butyl ether,dipropylene glycol n-butyl ether, tripropylene glycol methyl ether,tripropylene glycol n-propyl ether, tripropylene glycol t-butyl ether,tripropylene glycol n-butyl ether.

Non-limiting examples of other silicone solvents, in addition to thesiloxanes, are well known in the literature, see, for example, KirkOthmer's Encyclopedia of Chemical Technology, and are available from anumber of commercial sources, including GE Silicones, Toshiba Silicone,Bayer, and Dow Coming. For example, one suitable silicone solvent isSF-1528 available from GE Silicones.

Non-limiting examples of suitable glycerine derivative solvents includematerials having the following structure:

wherein R¹, R² and R³ are each independently selected from: H; branchedor linear, substituted or unsubstituted C₁-C₃₀ alkyl, C₂-C₃₀ alkenyl,C₁-C₃₀ alkoxycarbonyl, C₃-C₃₀ alkyleneoxyalkyl, C₁-C₃₀ acyloxy, C₇-C₃₀alkylenearyl; C₄-C₃₀ cycloalkyl; C₆-C₃₀ aryl; and mixtures thereof. Twoor more of R¹, R² and R³ together can form a C₃-C₈ aromatic ornon-aromatic, heterocyclic or non-heterocyclic ring.

Non-limiting examples of suitable glycerine derivative solvents include2,3-bis(1,1-dimethylethoxy)-1-propanol; 2,3-dimethoxy-1-propanol;3-methoxy-2-cyclopentoxy-1-propanol;3-methoxy-1-cyclopentoxy-2-propanol; carbonic acid(2-hydroxy-1-methoxymethyl)ethyl ester methyl ester; glycerol carbonateand mixtures thereof.

Non-limiting examples of other environmentally-friendly solvents includelipophilic fluids that have an ozone formation potential of from about 0to about 0.31, lipophilic fluids that have a vapor pressure of fromabout 0 to about 0.1 mm Hg, and/or lipophilic fluids that have a vaporpressure of greater than 0.1 mm Hg, but have an ozone formationpotential of from about 0 to about 0.31. Non-limiting examples of suchlipophilic fluids that have not previously been described above includecarbonate solvents (i.e., methyl carbonates, ethyl carbonates, ethylenecarbonates, propylene carbonates, glycerine carbonates) and/or succinatesolvents (i.e., dimethyl succinates).

“Ozone Reactivity” as used herein is a measure of a VOC's ability toform ozone in the atmosphere. It is measured as grams of ozone formedper gram of volatile organics. A methodology to determine ozonereactivity is discussed further in W. P. L. Carter, “Development ofOzone Reactivity Scales of Volatile Organic Compounds”, Journal of theAir & Waste Management Association, Vol. 44, Page 881-899, 1994. “VaporPressure” as used can be measured by techniques defined in Method 310 ofthe California Air Resources Board.

In one embodiment, the lipophilic fluid comprises more than 50% byweight of the lipophilic fluid of cyclopentasiloxanes (e.g., D5) and/orlinear analogs having approximately similar volatility, and optionallycomplemented by other silicone solvents.

The level of lipophilic fluid, when present in the treating compositionsaccording to the present invention, is from greater than about 50% toabout 99.99%, or from about 60% to about 95%, or from about 70% to about90% by weight of the treating composition.

Fabric Treatment Compositions

The fabric treatment composition for use in treating/cleaning fabricarticles may comprise a lipophilic fluid, a fabric treating agent havingone or more functional moieties, and optionally, water, polar solvents,cleaning adjuncts and/or fabric treating agents.

A given fabric treating agent, when present in the composition,typically comprises from about 0.01% to about 80%, or from about 0.5% toabout 60%, or from about 1% to about 50% by weight of the composition.The fabric treating agents are not required to be present at the sameconcentration. For example, an enzyme can be present at a level of about1/10 to about 1/100 of the level of a detersive surfactant.

When the composition is diluted with the lipophilic fluid to form thewash liquor, a given fabric treating agent, when present, typicallycomprises from about 0.0001% to about 50%, or from about 0.01% to about30%, or from about 1% to about 20% by weight of the wash liquor.

In some embodiments, polar solvents may optionally be incorporated intothe wash liquor as well. The polar solvent may be added as a componentof the fabric treatment composition or as a co-solvent of the lipophilicfluid in the wash liquor. The polar solvent can be water, and optionallyalso includes linear or branched C1-C6 alcohols, C1-C4 glycols andmixtures thereof.

When present, the polar solvent ranging from about 99% to about 1%, orfrom about 5% to about 40%, by weight of the composition; and cleaningadjuncts ranging from about 0.01% to about 50%, or from about 5% toabout 30%, by weight of the composition.

Contaminants

The contaminants that may enter the dry cleaning solvent during fabricarticle treating processes typically include laundry soils, especiallylipophilic laundry soils, such as nonionic surfactants, saturated andunsaturated fatty acids, mono-, di- and tri-glycerides, non-polarhydrocarbons, waxes and wax esters, lipids, and mixtures thereof.

The contaminants may also come from the fabric treating agents in thecomposition, including, but are not limited to: soil release polymers,detersive surfactants, bleaches, enzymes, perfumes, softening agents,finishing polymers, dyes, dye transfer inhibiting agents, dye fixatives,fiber rebuild agents, wrinkle reducing and/or removing agents, fiberrepair agents, perfume release and/or delivery agents, shape retentionagents, fabric and/or soil targeting agents, antibacterial agents,anti-discoloring agents, hydrophobic finishing agents, UV blockers,brighteners, pigments (e.g., Al₂O₃, TiO₂), pill prevention agents,temperature control agent, skin care lotions (comprising humectants,moisturizers, viscosity modifiers, fragrances, etc.), insect repellents,fire retardants, and mixtures thereof. Some of these fabric treatingagents are described in detail below.

Soil Release Polymers

The term “soil-release” as used herein refers to the ability of thefabric article to be washed or otherwise treated to remove soils thathave come into contact with the fabric article. The present inventiondoes not wholly prevent the attachment of soil to the fabric article,but hinders such attachment and improves the cleanability of the fabricarticle. Nonlimiting examples of soil release polymers suitable for useherein include fluorine-containing soil release polymers andsilicone-containing soil release polymers.

Examples of fluorine-containing soil release polymers (fluoro-SRPs)useful in the present invention can be a polymer derived fromperfluoroalkyl monomers, or from a mixture of perfluoroalkyl monomersand alkyl methacrylate monomers. The perfluoroalkyl monomer has theformula (a):R_(f)-Q-A-C(O)—C(R)═CH₂  (a)wherein R_(f) of formula (a) is a linear or branched perfluoroalkylgroup containing from 2 to about 20 carbon atoms; R of formula (a) is Hor CH₃; A is O, S, or N(R′); Q of formula (a) is alkylene of 1 to about15 carbon atoms, hydroxyalkylene of 3 to about 15 carbon atoms,—(C_(n)H_(2n))(OC_(q) H_(2q))_(m)—, —SO₂—NR′(C_(n)H_(2n))—, or—CONR′(C_(n)H_(2n))—; wherein R′ is H or alkyl of 1 to about 4 carbonatoms; n is 1 to about 15; q is 2 to about 4; and m is 1 to about 15.

In one embodiment, the fluoroalkyl monomer is a perfluoroalkylethyl(meth)acrylate. In another embodiment, the perfluoroalkyl carbon chainlength distribution by weight is about 50% of C8, about 29% of CIO,about 11% of C12, and the balance of C6, 14-carbon and longer chainlengths. This composition is available as ZONYL TA-N® from E. I. du Pontde Nemours and Company of Wilmington, Del. The proportion of fluoroalkylmonomer is at least about 70% relative to the total weight of copolymer.

The alkyl methacrylate monomer has the formula (b):R″—O—C(O)—C(R)═CH₂  (b)wherein R″ of formula (b) is independently selected from H, linear orbranched alkyl groups of about 1 to about 24 carbons, linear or branchedalkyl groups of about 1 to about 24 carbons modified to contain I to 3nitrogens, and mixtures thereof; and R of formula (b) is H or CH₃. Thealkyl (meth)acrylate is added so as to constitute 5-25% of the monomerchain units on a weight basis. In one embodiment, the alkyl methacrylateis stearyl methacrylate.

Exemplary fluoro-SRPs are available under the tradename REPEARL F35® inan aqueous suspension form from Mitsubishi, and under the tradenamesZONYL 7060®, ZONYL 8300®, and ZONYL 8787® from DuPont. Other suitablefluoro-SRPs are disclosed in WO 01/98384, WO 01/81285; JP 10-182814; JP2000-273067; WO 98/4160213, and WO 99/69126.

Exemplary silicone-containing soil release polymers (Si-SRPs) can havethe following formula (c):M_(a)D_(b)D′_(c)T_(d)(D_(e)M_(a))_(+d)  (c)wherein a of formula (c) is 0-2; b of formula (c) is 0-1000; c offormula (c) is 0-200; d of formula (c) is 0-1; e of formula (c) is0-1000, provided that a+c+d+e of formula (c) is at least 1;

M of formula (c) is R¹ _(3-f)X_(f)SiO_(1/2) wherein R′ of formula (c) isindependently H, or a monovalent hydrocarbon group, X of formula (c) ishydroxyl, alkoxy group, and f is 0 or 1;

D of formula (c) is R⁴ ₂SiO_(1/2) wherein R⁴ of formula (c) isindependently H or a monovalent hydrocarbon group;

D′ of formula (c) is R⁵ ₂SiO_(2/2) wherein R⁵ of formula (c) isindependently H, a monovalent hydrocarbon group or(CH₂)_(g)(C₆Q₄)_(h)(A)_(i)-[(L)_(j)-(A′)_(k)-]_(l), wherein g of formula(c) is 1-10; h of formula (c) is 0 or 1; i of formula (c) is 0-5; j offormula (c) is 0-3; k of formula (c) is 0 or 1; 1 of formula (c) is0-10; C₆Q₄ of formula (c) is unsubstituted or substituted with Q offormula (c) is independently H, C₁₋₁₀ alkyl, C₁₋₁₀ alkenyl, and mixturesthereof; A and A′ of formula (c) are each independently a linking moietyrepresenting an ether, an amido, an amino, a C₁₋₄ fluoroalkyl, a C₁₋₄fluoroalkenyl, an ammonium, and mixtures thereof; L of formula (c) is aC₁₋₃₀ straight chained or branched alkyl or alkenyl or an aryl which isunsubstituted or substituted;

T of formula (c) is R⁶ ₁SiO_(3/2) wherein R₆ of formula (c) is(CH₂)_(m)(C₆Q₄)_(n)(A)_(o)-[(L)_(p)-(A′)_(q)-]_(r), wherein m of formula(c) is 1-10; n of formula (c) is 0 or 1; o of formula (c) is 0-5; p offormula (c) is 0-3; q of formula (c) is 0 or 1; r of formula (c) is0-10; C₆Q₄ of formula (c) is unsubstituted or substituted with Q offormula (c) is independently H, C₁₋₁₀ alkyl, C₁₋₁₀ alkenyl, and mixturesthereof; A and A′ of formula (c) are each independently a linking moietyrepresenting an ether, an amido, an amino, a C₁₋₄ fluoroalkyl, a C₁₋₄fluoroalkenyl, an ammonium, and mixtures thereof; L of formula (c) is aC₁₋₃₀ straight chained or branched alkyl or alkenyl or an aryl which isunsubstituted or substituted.

-   Exemplary Si-SRPs are commercially available as DF104, DF1040,    SM2125, SM2245, SM2101, SM2059 from GE, and Dow Corning 75SF®    Emulsion.

Also suitable for use as soil release polymer in the present inventionare water soluble modified celluloses which include, but are not limitedto: carboxymethylcellulose, hydroxypropylcellulose, methylcellulose, andlike compounds. These compounds, and other suitable compounds, aredescribed in Kirk Othmer Encyclopedia of Chemical Technology, 4^(th)Edition, vol. 5, pages 541-563, under the heading of “Cellulose Ethers”,and in the references cited therein.

Another class of suitable soil release polymers may comprise blockcopolymers of polyalkylene terephthalate and polyoxyethyleneterephthalate, and block copolymers of polyalkylene terephthalate andpolyethylene glycol. These compounds are disclosed in details in arediscussed in U.S. Pat. No. 6,358,914 and U.S. Pat. No. 4,976,879.

Another class of soil release polymer is a crystallizable polyestercomprising ethylene terephthalate monomers, oxyethylene terephthalatemonomers, or mixtures thereof. Examples of this polymer are commerciallyavailable as Zelcon 4780® (from DuPont) and Milease T® (from ICI). Amore complete disclosure of these soil release agents is contained in EP0 185 427 A1.

Detersive Surfactants

The surfactant suitable for use in the present invention has the generalformula:Y_(u)-(L_(t)-X_(v))_(x)—Y′_(w)  (I)L_(y)-(X_(v)-Y_(u))_(x)—L′_(z)  (II)

-   -   and mixtures thereof;        wherein L and L′ are solvent compatibilizing (or lipophilic)        moieties, which are independently selected from:    -   (a) C1-C22 alkyl or C4-C12 alkoxy, linear or branched, cyclic or        acyclic, saturated or unsaturated, substituted or unsubstituted;    -   (b) siloxanes having the formula:        M_(a)D_(b)D′_(c)D″_(d)        wherein a is 0-2; b is 0-1000; c is 0-50; d is 0-50, provided        that a+c+d is at least 1;

M of formula (III) is R¹ _(3-e)X_(e)SiO_(1/2) wherein R¹ of formula(III) is independently H, or a monovalent hydrocarbon group, X offormula (III) is hydroxyl group, and e is 0 or 1;

D of formula (III) is R⁴ ₂SiO_(2/2) wherein R⁴ of formula (III) isindependently H or a monovalent hydrocarbon group;

D′ of formula (III) is R⁵ ₂SiO_(2/2) wherein R⁵ of formula (II) isindependently R² of formula (III) provided that at least one R⁵ offormula (III) is(CH₂)_(f)(C₆Q₄)_(g)O—(C₂H₄O)_(h)-(C₃H₆O)_(i)(C_(k)H_(2k))_(j)-R³,wherein R³ of formula (III) is independently H, a monovalent hydrocarbongroup or an alkoxy group, f of formula (III) is 1-10, g of formula (III)is 0 or 1, h of formula (III) is 1-50, i of formula (III) is 0-50, j offormula (III) is 0-50, k of formula (III) is 4-8; C₆Q₄ of formula (III)is unsubstituted or substituted with Q of formula (III) is independentlyH, C₁₋₁₀ alkyl, C₁₋₁₀ alkenyl, and mixtures thereof.

D″ of formula (III) is R⁶ ₂SiO_(2/2) wherein R⁶ of formula (III) isindependently H, a monovalent hydrocarbon group or(CH₂)_(l)(C₆Q₄)_(m)(A)_(n)-[(L)_(o)-(A′)_(p)-]_(q)-(L′) _(r)Z(G)_(s),wherein 1 of formula (III) is 1-10; m of formula (III) is 0 or 1; n offormula (III) is 0-5; o of formula (III) is 0-3; p of formula (III) is 0or 1; q of formula (III) is 0-10; r of formula (III) is 0-3; s offormula (III) is 0-3; C₆Q₄ of formula (III) is unsubstituted orsubstituted with Q of formula (III) is independently H, C₁₋₁₀ alkyl,C₁₋₁₀ alkenyl, and mixtures thereof; A and A′ of formula (III) are eachindependently a linking moiety representing an ester, a keto, an ether,a thio, an amido, an amino, a C₁₋₄ fluoroalkyl, a C₁₋₄ fluoroalkenyl, abranched or straight chained polyalkylene oxide, a phosphate, asulfonyl, a sulfate, an ammonium, and mixtures thereof; L and L′ offormula (III) are each independently a C₁₋₃₀ straight chained orbranched alkyl or alkenyl or an aryl which is unsubstituted orsubstituted; Z of formula (III) is a hydrogen, carboxylic acid, ahydroxy, a phosphate, a phosphate ester, a sulfonyl, a sulfonate, asulfate, a branched or straight-chained polyalkylene oxide, a nitryl, aglyceryl, an aryl unsubstituted or substituted with a C₁₋₃₀ alkyl oralkenyl, a carbohydrate unsubstituted or substituted with a C₁₋₁₀ alkylor alkenyl or an ammonium; G of formula (III) is an anion or cation suchas H⁺, Na⁺, Li⁺, K⁺, NH₄ ⁺, Ca⁺², Mg⁺², Cl⁻, Br⁻, I⁻, mesylate ortosylate;

Y and Y′ are hydrophilic moieties, which are independently selected fromhydroxy; polyhydroxy; C1-C3 alkoxy; mono- or di- alkanolamine; C1-C4alkyl substituted alkanolamine; substituted heterocyclic containing O,S, N; sulfates; carboxylate; carbonate; and when Y and/or Y′ is ethoxy(EO) or propoxy (PO), it must be capped with R, which is selected fromthe group consisting of:

-   -   (i) a 4 to 8 membered, substituted or unsubstituted,        heterocyclic ring containing from 1 to 3 hetero atoms; and    -   (ii) linear or branched, saturated or unsaturated, substituted        or unsubstituted, cyclic or acyclic, aliphatic or aromatic        hydrocarbon radicals having from about 1 to about 30 carbon        atoms;

X is a bridging linkage selected from O; S; N; P; C1 to C22 alkyl,linear or branched, saturated or unsaturated, substituted orunsubstituted, cyclic or acyclic, aliphatic or aromatic, interrupted byO, S, N, P; glycidyl, ester, amido, amino, PO42-, HPO4-, PO32-, HPO3-,which are protonated or unprotonated;

u and w are integers independently selected from 0 to 20, provided thatu+w≧1;

t is an integer from 1 to 10;

v is an integer from 0 to 10;

x is an integer from 1 to 20; and

y and z are integers independently selected from 1 to 10.

Yet another class of suitable surfactants are organosulfosuccinates,with carbon chains of from about 6 to about 20 carbon atoms. In oneembodiment, the organosulfosuccinates contain dialkly chains, each withcarbon chains of from about 6 to about 20 carbon atoms. In anotherembodiment, the organosulfosuccinates have chains containing aryl oralkyl aryl, substituted or unsubstituted, branched or linear, saturatedor unsaturated groups. Nonlimiting commercially available examples ofsuitable organosulfosuccinate surfactants are available under the tradenames of Aerosol OT® and Aerosol TR-70® (ex. Cytec).

Bleaches

Nonlimiting examples of suitable bleaches are selected from the groupconsisting of catalytic metal complexes, activated peroxygen sources,bleach activators, bleach boosters, photobleaches, free radicalinitiators and hyohalite bleaches.

Examples of suitable catalytic metal complexes include, but are notlimited to, manganese-based catalysts such as Mn^(IV) ₂(u-O)₃(1,4,7-trimethyl-1,4,7-triazacyclononane)₂(PF₆) ₂ disclosed inU.S. Pat. No. 5,576,282, cobalt based catalysts disclosed in U.S. Pat.No. 5,597,936 such as cobalt pentaamine acetate salts having the formula[Co(NH₃)₅OAc] T_(y), wherein “OAc” represents an acetate moiety and“T_(y)” is an anion; transition metal complexes of a macropolycyclicrigid ligand—abreviated as “MRL”. Suitable metals in the MRLs includeMn, Fe, Co, Ni, Cu, Cr, V, Mo, W, Pd, and Ru in their various oxidationstates. Examples of suitable MRLs include:Dichloro-5,12-diethyl-1,5,8,12-tetraazabicyclo[6.6.2]hexadecaneManganese(II),Dichloro-5,12-diethyl-1,5,8,12-tetraazabicyclo[6.6.2]hexadecaneManganese(III) Hexafluorophosphate andDichloro-5-n-butyl-12-methyl-1,5,8,12-tetraazabicyclo[6.6.2]hexadecaneManganese(III). Suitable transition metal MRLs are readily prepared byknown procedures, such as taught for example in WO 00/332601, and U.S.Pat. No. 6,225,464.

Suitable activated peroxygen sources include, but are not limited to,preformed peracids, a hydrogen peroxide source in combination with ableach activator, or a mixture thereof. Suitable preformed peracidsinclude, but are not limited to, compounds selected from the groupconsisting of percarboxylic acids and salts, percarbonic acids andsalts, perimidic acids and salts, peroxymonosulfuric acids and salts,and mixtures thereof. Suitable sources of hydrogen peroxide include, butare not limited to, compounds selected from the group consisting ofperborate compounds, percarbonate compounds, perphosphate compounds andmixtures thereof. Suitable types and levels of activated peroxygensources are found in U.S. Pat. Nos. 5,576,282, 6,306,812 B1 and6,326,348 B1 that are incorporated by reference.

Suitable bleach activators include, but are not limited to,perhydrolyzable esters and perhydrolyzable imides such as, tetraacetylethylene diamine, octanoylcaprolactam, benzoyloxybenzenesulphonate,nonanoyloxybenzenesulphonate, benzoylvalerolactam,dodecanoyloxybenzenesulphonate.

Suitable bleach boosters include, but are not limited to, thosedescribed U.S. Pat. No. 5,817,614.

Enzymes

Nonlimiting examples of suitable enzymes include proteases, amylases,cellulases, lipases, and others. Suitable proteases include subtilisinsfrom Bacillus e.g. subtilis, lentus, licheniformis, amyloliquefaciens(BPN, BPN′), alcalophilus,] under the tradenames of Esperase®,Alcalase®, Everlase® and Savinase® (from Novozymes), BLAP and variants(from Henkel). Other suitable proteases are described in EP130756, WO91/06637, WO 95/10591 and WO99/20726. Suitable amylases (α and/or β) aredescribed in WO 94/02597 and WO 96/23873. Nonlimiting examples ofcommercially available amylases include Purafect Ox Am® (from Genencor)and Termamyl®, Natalase®, Ban®, Fungamyl® and Duramyl(® (fromNovozymes). Suitable cellulases include bacterial or fungal cellulases,such as those produced by Humicola insolens, particularly DSM 1800[commercially avaialbe as Carezyme®]. Other suitable cellulases are theEGIII cellulases produced by Trichoderma longibrachiatum. Suitablelipases include those produced by Pseudomonas and Chromobacter groups.Nonlimiting examples of commercially available lipases includeLipolase®, Lipolase Ultra®, Lipoprime® and Lipex® from Novozymes. Alsosuitable for use herein are cutinases [EC 3.1.1.50]; esterases;carbohydrases such as mannanase (U.S. Pat. No. 6,060,299); pectate lyase(WO 99/27083) cyclomaltodextringlucanotransferase (WO 96/33267); andxyloglucanase (WO 99/02663). Additionally, nonlimiting examples ofbleaching enzymes include peroxidases, accases, oxygenases, (e.g.catechol 1,2 dioxygenase, lipoxygenase (WO 95/26393), (non-heme)haloperoxidases.

Perfumes and Perfume Delivery Systems

As used herein the term “perfume” refers to any odoriferous material.Suitable perfumes include but are not limited to one or more aromaticchemicals, naturally derived oils and mixtures thereof. Chemical classesfor such aromatic chemicals and essential oils include but are notlimited to alcohols, aldehydes, esters, ketones. Perfume is commonlyprovided with a perfume delivery system.

Suitable perfume delivery systems include but are not limited to perfumeloaded cyclodextrins, amine assisted delivery compositions,polymer-assisted perfume systems, reactive/pro-perfume systems andinorganic carrier systems. Perfume loaded cyclodextrin deliverycompositions comprise perfume materials or blends complexed withcyclodextrin type materials—a majority of the cyclodextrin may bealpha-, beta-, and/or gamma-cyclodextrin, or simply beta-cyclodextrin.Processes for producing cyclodextrins and cyclodextrin deliverycompositions are further described in U.S. Pat. Nos. 3,812,011,4,317,881, 4,418,144 and 5,552,378.

Amine assisted delivery systems comprise one or more perfumes and apolymeric and/or non-polymeric amine material that is added separatelyfrom the perfume to the finished products. Such systems are described inWO 03/33635 and WO 03/33636.

Polymer-assisted delivery systems use physical bonding of polymericmaterials and perfumes to deliver perfume materials. Suitable polymerassisted systems, include but not limited to, reservoir systems(coacervates, microcapsules, starch encapsulates), and matrix systems(polymer emulsions, latexes). Such systems are further described in WO01/79303, WO 00/68352, WO 98/28339, and U.S. Pat. Nos. 5,188,753 and4,746,455.

Reactive/pro perfumes systems include, but are not limited to, polymericpro-perfumes that comprise perfume materials, typically aldehyde orketone perfumes, reacted with polymeric carriers, typically nitrogenbased carriers, prior to addition to a product; non-polymericpro-perfume systems that comprise perfume materials reacted withnon-polymeric materials for example, Michael adducts (β-amino ketones),Schiff bases (imines), oxazolidines, β-Keto Esters, orthoesters andphoto pro-perfumes. Such systems are further described in WO 00/24721,WO 02/83620 and U.S. Pat. Nos. 6,013,618 and 6,451,751.

Inorganic carrier systems that comprise inorganic materials (porouszeolites, silicas, etc.) that are loaded with one or more perfumematerials. Such systems are further described in U.S. Pat. Nos.:5,955,419, 6,048,830 and 6,245,732.

Softening Agents

Suitable fabric softening agents or actives include, but are not limitedto, diester quaternary ammonium compounds (DEQA); polyquaternaryammonium compounds; triethanolamine esterified with carboxylic acid andquaternized (so called “esterquat”); amino esterquats; cationicdiesters; betaine esters; cationic polymers of cyclic polyols and/orreduced saccharides (so called “polyol polyesters” or “Sefose”);silicone or silicone emulsions comprising aminosilicones, cationicsilicones, quat/silicone mixtures; functionalized PDMS; and mixturesthereof.

Deposition aids, typically comprise a cationic moiety, can also be usedin combination with softening agents.

Nonlimiting examples of quaternaty ammonium type softeners may beselected from the group consisting of:N,N-dimethyl-N,N-di(tallowyloxyethyl) ammonium methylsulfate,N-methyl-N-hydroxyethyl-N,N-di(canoyloxyethyl) ammonium methylsulfateand mixtures thereof.

Additional examples of non-silicone fabric softening agents anddeposition aids are described in EP 902 009; WO 99/58492; U.S. Pat. No.4,137,180; WO 97/08284; WO 00/70004; WO 00/70005; WO 01/46361; WO01/46363; WO 99/64661; WO 99/64660; JP 11-350349; JP 11-081134; and JP11-043863. Additional examples of silicone fabric softening agents anddeposition aids are described in U.S. Pat. No. 4,448,810; U.S. Pat. No.4,800,026; U.S. Pat. No. 4,891,166; U.S. Pat. No. 5,593,611; EP 459 821;EP 530 974; WO 92/01773; WO 97/32917; WO 00/71806; WO 00/71807; WO01/07546; WO 01/23394; JP 2000-64180; JP 2000-144199; JP 2000-178583;and JP 2000-192075.

Finishing Polymers

The finishing polymers can be natural, or synthetic, and can act byforming a film, and/or by providing adhesive properties. For example,the present invention can optionally use film-forming and/or adhesivepolymer to impart shape retention to fabric, particularly clothing. By“adhesive” it is meant that when applied as a solution or a dispersionto a fiber surface and dried, the polymer can attach to the surface. Thepolymer can form a film on the surface, or when residing between twofibers and in contact with the two fibers, it can bond the two fiberstogether.

Nonlimiting examples of the finishing polymer that are commerciallyavailable are: polyvinylpyrrolidone/dimethylaminoethyl methacrylatecopolymer, such as Copolymer 958®, molecular weight of about 100,000 andCopolymer 937, molecular weight of about 1,000,000, available from GAFChemicals Corporation; adipic acid/dimethylaminohydroxypropyldiethylenetriamine copolymer, such as Cartaretin F-4® and F-23,available from Sandoz Chemicals Corporation; methacryloyl ethylbetaine/methacrylates copolymer, such as Diaformer Z-SM®, available fromMitsubishi Chemicals Corporation; polyvinyl alcohol copolymer resin,such as Vinex 2019®, available from Air Products and Chemicals orMoweol®, available from Clariant; adipic acid/epoxypropyldiethylenetriamine copolymer, such as Delsette 101®, available fromHercules Incorporated; polyamine resins, such as Cypro 515®, availablefrom Cytec Industries; polyquaternary amine resins, such as Kymene557H®, available from Hercules Incorporated; andpolyvinylpyrrolidone/acrylic acid, such as Sokalan EG 310®, availablefrom BASF.

Additional examples of suitable finishing polymers include but are notlimited to starch carboxymethyl cellulose, hydroxypropyl methylcellulose, and mixtures thereof.

Other Fabric Treating Agents

Nonlimiting examples of suitable UV protection agents includebenzopyrrolidone derivatives (WO 00/65142); sacrificial photofadingprevention to retard color fading and/or cinnamate derivatives such aslevafix in combination with di-long chain quats (WO 00/00577);aminonapthalene derivatives: fabric substantive sunscreens (WO99/50379); deposition of UV absorbers via cellulose monoacetate; methoxycinnamate derivatives (WO 00/18861 and WO 00/18862); esters of PVAand/or SCMC with UV absorbers to enhance active deposition (WO00/18863); deposition of 2 ethylhexyl 4 methoxy cinnamate innon-ionic/cationic product (WO 97/44422); deposition of UV absorbers ofClogP>4 from rinse products (WO 97/44424); cationic UV absorbers (WO98/30663); use of hindered amines to retard UV fading of dyed fabrics(WO 01/38470 and WO 01/07550); cationic singlet oxygen quenchers toretard photofading (EP 832 967); NCO containing polymers in combinationwith water soluble sunscreens (WO 98/49259); antioxidant+tinuvin inrinse conditioner (U.S. Pat. No. 5,962,402); benzotriazole UV absorbers(U.S. Pat. No. 5,733,855).

Nonlimiting examples of suitable dye transfer inhibiting (DTI) agentsand/or dye fixing agents include black dye to restore fabric color (WO99/66019); vinyl-imidazole-acrylic acid copolymers as DTI agents (WO00/17296); llama UHH antibodies to prevent Red 6 dye transfer (WO99/46300); acrylic/vinylimidazole copolymers as DTI agents (WO98/30664); compositions containing selected DTI agents and silica orzeolite as a carrier material; Chromabond+Gasil silica or zeolite;Tinofix; Burcofix; PVP (N-polyvinylpyrrolidone); photoinitiators;hydroxyacetophenone; phosphine oxide derivatives; compositions withreactive polymer (eg amide/epichlorhydrin resin) and reactive anionicpolymer and carrier for improved dye fix. (WO 01/25386); PVP/PVI(N-vinylpyrrolidone/N-vinylimidazole copolymer) compositions (U.S. Pat.No. 5,977,046 and WO 97/23591); hyperbranched polymer/dendrimer (EP 875521); dendritic macromolecule, amine containing (U.S. Pat. No. 5,872,093and EP 779 358); propylenediamine and piperazine (WO 00/15745) for dyefixing benefits; CMC combinations to reduce fiber mechanical damage anddye loss (WO 00/22079, WO 00/22078, WO 00/22077 and WO 00/22075);dimethyl diallyl based polymers as dye fixing agents (WO 00/56849);polymeric cyclic amines (WO 99/14299); copolymers of epichlorhydrin andcyclic amines together with semi polar nonionics (WO 01/32815 and WO01/32816); high molecular weight polymers ofN-vinylimidazole/N-vinylpyrrolidone as DTI agent (DE 19 621 509);polycationics as dye fixatives (DE 19 643 281); aminosilicones as dyeremoval protectors and prolonged perfume release (WO 98/39401) andmixtures thereof.

Nonlimiting examples of suitable wrinkle reducing and/or removing agentsinclude use of oxidised polyethylene (DE19 926 863); sulfated castor oiland/or ethoxylated silicones and/or amino PDMS and/or polyacrylamides;Magnasoft® SRS, Silwet® L-7622 (WO 00/24853 and WO 00/24857);ethoxylated PDMS and acrylic polymers (WO 00/27991); emulsion of highviscosity silicone oil and esterquat (WO 00/71806); aliphaticunsaturated hydrocarbons; squalene; paraffin (WO 01/34896);styrene-isoprene or styrene butadiene polymers (WO 01/38627);incorporation of silicone polymers into crosslinked cellulose; siliconecarboxylates or silanol containing reacted with acid treated cellulose(WO 01/44426); acrylics with PDMS; arabinogalactans; silicone emulsions;isomaltosuccinamides (WO 00/24851 and WO 00/24856 and WO 00/24858);natural cotyledon extract (WO 01/07554); cellulosic based anti-wrinkletechnology containing triazine or pyrimidine units and a cross linkingagent (WO 01/23660); cationic polyamide/epichlorhydrin resin andsilicone lubricant compositions (EP 1 096 056); wrinkle reducingcompositions containing silicone and film forming polymer (WO 96/15309);wrinkle reducing compositions containing non-ionic polyhydric alcohol(WO 99/55948 and WO 99/55949); curable aminofunctionalizedsilicone/fabric softening compositions (U.S. Pat. No. 5,174,912);polyacrylate/dihydroxyethylurea (WO 01/16262) and mixtures thereof. Itis understood that some of these wrinkle reducing agents also providefabric softening benefits.

Nonlimiting examples of fabric rebuild agents and/or fiber repair agentsinclude production of N-alkoxylated chitin/chitosan as reviving agent(DE 10 019 140); cellulose monoacetate as fabric rebuild agent, such asthe use of cellulosic polymers as deposition aids for various benefitagents (WO 00/18860, WO 00/18861 and WO 00/18862); cationicpolyamine/epichlorhydrin resin crosslinked as fabric rebuild agent;Apomul SAK® (WO 01/25386); polymeric materials capable of selfcrosslinking or reacting with cellulose; includes reactive polyurethanes(WO 01/27232); compositions containing polyssacharide gum of lowmolecular weight such as locust bean gum, such gums can be produced insitu via enzyme cleavage, such as Xyloglucans (WO 00/40684 and WO00/40685); polysaccharide/cellulose ester (acetate); specificsubstituted rebuild polymers (WO 01/72936 and WO 01/72940 to WO01/72944); hydrophobized CMC to prevent fibre entanglement (WO 00/42144and WO 00/47705); high molecular weight PEIs crosslinked with dibasicacids or epichlorhydrin for abrasion resistance (WO 00/49122); propylenediamine polymer derivatives for abrasion resistance (WO 00/49123);lysine caprolactam polymers for abrasion resistance (WO 00/49125); filmforming cellulose ethers applied from rinse conditioner (WO 00/65015);lysine/amine or adipic acid copolymers for fiber appearance (WO 99/07813and WO 99/07814) and mixtures thereof.

Nonlimiting examples of suitable shape retention agents includecompositions containing PAE resin (e.g., Apomul SAK) and silicone toprovide dimensional stability (WO 00/15747 and WO 00/15748); cationicamine/epichlorhydrin resin (PAE resin) as fabric shape retention agentsfor dryer applications (WO 00/15755); anionic polymer capable of selfcross linking and reacting with cellulose, eg carbamoyl sulfonateterminated blocked isocyanates; provide dimensional stability (WO01/25387) and mixtures thereof.

Nonlimiting examples of suitable targeting agents are developed intechnologies such as attachment of large molecules to cellulose bindingpolysaccharides (WO 99/36469); attachment of antibodies to functionalmaterial and adsorption onto fabric surface (WO 01/46364 and WO01/48135); proteins having a cellulosic binding domain (CBD) attached toparticles via antibody link, enhancement of perfume containingcoacervates onto cotton (WO 01/46357); delivery of benefit agent tofabric via peptide or protein deposition aid (WO 98/00500); benefitagent attached to mimic cellulose binding domain (WO 01/34743 and WO01/32848) and mixtures thereof.

Nonlimiting examples of suitable irritant reducing agents includereduced irritancy of as laundered fabrics via treatment with Leverquaternary ammonium materials (WO 00/17297).

Nonlimiting examples of suitable anti-discoloring agents includephosphonated terminated polyacrylate to provide lower yellowingpotential during fabric bleaching (DE 19 904 230).

Nonlimiting examples of suitable hydrophobic finishing agents includepolylysine as hydrophobic finishing agent (DE 19 902 506).

Nonlimiting examples of suitable antibacterial agents includecombination of amber and musk materials to mask malodor (WO 98/56337);antibacteriocidal compositions containing 5-chlorosalicylanilide (WO01/60157); antimicrobial compositions containing aminoalkyl silicone,improved surface residuality (WO 96/19194); antimicrobial polypeptides(WO 96/28468); antimicrobial compositions containing aromatic alcoholsand phenols (WO 98/01524); antimicrobial activity of alcohols (WO97/21795); betaine compositions with good antimicrobial activity (WO97/43368 and WO 97/43369); high pH non-ionic solutions as antimicrobialagents (WO 01/44430); capsule for controlled release of textiletreatment agents (DE 19 931 399); composition containingbenzylakylammonium, zinc PTO, climbazole (WO 98/01527);alkyldimethylammonium and alcohol ehtoxylates as effective antibacterialcompositions (GB 2 322 552); cyclohexyl esters for odor neutralization(WO 01/43784); alkoxy disulphide antimicrobial agents (EP 1 008 296);bromofuranones as antibacterial agents (WO 01/43739) and mixturesthereof.

Brighteners can be organic compounds that absorb the invisibleultraviolet (UV) radiation energy and converts this energy into thelonger wavelength radiation energy. The terms “brightener”, “opticalbrightener” and “whitener” are used interchangeably. Nonlimitingexamples of brighteners include derivatives of stilbene, pyrazoline,coumarin, carboxylic acid methinecyannines,dibenzothiophene-5,5-dioxide, azoles, 5- and 6-membered ringheterocycles, and the like. Examples of brighteners are disclosed in“The Production and Application of Fluorescent Brightening Agents”, M.Zahradnik, published by John Wiley & Sons, New York (1982).

Chemical Modification of the Contaminants

The present invention is directed to processes for enhanced removal ofcontaminants from a used dry cleaning solvent by modifying thecontaminants. More specifically, the original contaminants contains oneor more functional moieties that can be modified.

The purification process comprises a first step of providing a mixtureof a dry cleaning solvent and at least one contaminant. The mixture maybe generated by exposing a fabric article to a dry cleaning solvent orfabric treatment composition comprising fabric treating agents. Inspecific embodiments, water may be present in the fabric treatmentcomposition or may be applied from a separate source to the fabricarticle in this fabric article treating step. Then, the used drycleaning solvent, containing laundry soils and/or fabric treatingagents, can be collected and used as the mixture needing purification inthe present method. The fabric article treating methods to provide theused solvent or mixture include conventional immersive cleaning methodsas well as the non-immersive cleaning methods disclosed in U.S. PatentPublications US 20020133886-A1 and US 20020133885-A1.

The purification process of the present invention include the step ofmodifying one or more functional moieties of the contaminants (e.g.,fabric treating agents or laundry soils) in their original form. Thecontaminants can be polymeric or non-polymeric materials. When thecontaminant is a polymer, the functional moieties can be located in thepolymer backbone or at the chain ends. More specifically, in thismodification step, the one or more functional moieties undergo chemicalchanges such that the modified contaminant becomes less soluble in orless compatible with the dry cleaning solvent, thus, it can be separatedfrom the solvent more easily. In one embodiment, the modifiedcontaminant is more hydrophilic than the original contaminant. Inanother embodiment, the modified contaminant has a lower molecularweight than the original contaminant. In yet another embodiment, themodified contaminant is more polar than the original contaminant. Instill another embodiment, the modified contaminant has a highermolecular weight than the original contaminant.

As used herein, the term ‘less compatible’ or “less soluble” means thedifference in Hansen solubility parameters of the dry cleaning solventand the contaminant becomes larger upon modification of the contaminant.It is known that Hansen solubility parameter is based on the sum of theeffects of hydrogen bonding, polarity and dispersion, which aredetermined by the molecular structure. As a contaminant gets modified bythe chemical modifying agents of the present invention, its solubilityparameter changes such that the contaminant may separate out of thesolvent, as indicated by cloudiness, aggregation, precipitation, and thelike.

The purification process of the present invention include the step ofmodifying the mixture in such a manner that the contaminants arerendered less soluble in the mixture to facilitate the separation of thecontaminants and the solvent.

Modification of the mixture can be effected by contacting the mixturewith a purification agent, such as an ionic strength modifier, a pHmodifier, a flocculating agent, a gelling agent, a biological agent, aliquid extraction agent, and mixtures thereof. As the mixture getsmodified by the purification agents of the present invention, thecontaminants become less soluble in the modified mixture and thecontaminants may begin to separate out of the bulk solvent, as indicatedby cloudiness, precipitate forming, and the like.

The separation step of the purification process of the present inventionis the separation of the modified contaminants from the dry cleaningsolvent. Suitable separation methods are disclosed herein below.

The dry cleaning solvent or composition thus purified can be used asworking solvent in subsequent fabric article treatment cycles. In oneembodiment of the invention, the purified dry cleaning solvent orcomposition can be collected and/or reformulated and re-used immediatelyin several additional fabric treating cycles before they need to gothrough the purification process again. In another embodiment of theinvention, the purified dry cleaning solvent or composition can beremoved from the fabric treating system, stored and used later as theworking solvent or composition in another system or another fabrictreating cycle.

Further, the purification process of the present invention may beapplied to the solvent or composition via an in-line (e.g., in thecleaning cycle) component of the cleaning system or as an accessory(e.g., post fabric treating cycle) component of the fabric treatingsystem.

It is recognized that in each purification cycle, a sufficient amount ofthe contaminants is removed from the dry cleaning solvent or compositionsuch that the level of contaminants in the purified solvent orcomposition does not impair its performance when it is used as theworking solvent or reformulated (by replacing the fabric treatingactives that have been removed and/or modified in this purificationprocess to the level in the original composition) as the workingcomposition in subsequent fabric article treating cycles. Where thecontaminant is a fabric treatment agent, the removal of fabric treatingagents in the purification process can be 100% removal of fabrictreating agents, but it does not have to be. Removal of about 50% toabout 100% removal of fabric treating agents present in the used solventor composition can be sufficient. The type of fabric articles and thetype of fabric treating agent are factors influencing the level offabric treating agents that may remain in the purified solvent orcomposition without impairing its cleaning performance. That is, thepurified solvent or composition may comprise a higher level of one typeof fabric treating agent than another. For example, the level of dyesmay be present from about 0.0001% to about 0.1%, or from about 0.00001%to about 0.1%, or from about 0% to about 0.01% by weight of the workingsolvent. On the other hand, the level of detersive surfactant in thepurified solvent may be from about 0.001% to about 20%, or from about0.0001% to about 5 %, or from about 0% to about 1%.

Chemical Modification of the Contaminants

Reactive chemistry directed to the one or more functional moieties ofthe contaminants provides several advantages. First, reactive chemistrycan be conducted in the non-thermal (i.e., does not involvedistillation), low temperature and ambient pressure conditions. Second,reactive chemistry (e.g., oxidation) can be targeted to oxidative siteson the contaminants. Third, by converting the contaminants into lesssoluble or less compatible species, they may precipitate out of thesolvent and thus, can be easily removed by known techniques, such asdecantation, centrifugation, and the like. In situations where themodified contaminants do not readily precipitate out of the solvent,other techniques (such as dialysis) can be applied to facilitate theseparation.

In one aspect of the invention, a mixture of a lipophilic fluid and afabric care agent containing functional moieties selected from the groupconsisting of acetals, ketals, orthoesters, ethers, amides, imides, andcombinations thereof is exposed to an acid such that these functionalmoieties undergo hydrolysis, thereby transforming the contaminant to amodified form, which can be one or more lower molecular weight speciesand/or more polar species, compared to the original form of thecontaminant. The modified contaminant becomes less compatible with thelipophilic fluid and can be more easily separated from the lipophilicfluid in the separation step.

The transformation of the functional moieties is illustratedschematically below:

Nonlimiting examples of acids suitable for use herein includeAmberlyst-15, acetic acid, oxalic acid, trifluoroacetic acid, formicacid, hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, andvarious Lewis acids.

In another aspect of the invention, a mixture of a lipophilic fluid anda fabric care agent containing functional moieties selected from thegroup consisting of esters, carbonates, ester-quaternary nitrogen, andcombinations thereof, is exposed to a base or an enzyme such that thesefunctional moieties undergo hydrolysis, thereby transforming thecontaminant to a modified form, which can be one or more lower molecularweight species and/or more polar species, compared to the original formof the contaminant. The modified contaminant becomes less compatiblewith the lipophilic fluid and can be more easily separated from thelipophilic fluid in the separation step. The transformation of thefunctional moieties is illustrated schematically below:

Nonlimiting examples of bases suitable for use herein includebicarbonate and carbonate salts of alkali and alkaline earth metals,hydroxy salts of alkali and alkaline earth metals, alkoxides, guanidine,secondary and tertiary alkyl amines. Enzymes such as lipases andesterases are suitable for use as hydrolyzing agents in the presentinvention.

In yet another aspect of the invention, a mixture of a lipophilic fluidand a fabric care agent containing functional moieties which areunsaturated C═C bonds (e.g., alkenyls), is exposed to an oxidizing agentsuch that these functional moieties undergo oxidation, therebytransforming the contaminant to a modified form, which can be one ormore lower molecular weight species and/or more polar species, comparedto the original form of the contaminant. The modified contaminantbecomes less compatible with the lipophilic fluid and can be more easilyseparated from the lipophilic fluid in the separation step. Theoxidative transformations can be either stoichiometric or catalytic andinclude, but are not limited to, ozonolysis, dihydroxylation,epoxidation, Wacker reaction, and oxidative cleavage. The transformationof the functional moieties is illustrated schematically below:

Exemplary oxidizing agents include, but are not limited to, ozone;persulfates; periodates; perchlorates; perborates; peroxydisulfates;peracetic acid; hydrogen peroxide; chlorine dioxide; hypochlorites;permanganates; enzymes; and mixtures thereof. Some of these oxidizingagents may be applied to the contaminated mixtures in their salt formcontaining a counterion of the alkaline or alkaline earth metals, suchas sodium ion, potassium ion, magnesium ions, calcium ions, and thelike.

Enzymes suitable for use as the oxidizing agents in the presentinvention include, but are not limited to, mono-oxygenase anddi-oxygenase, alcohol dehydrogenase, alkyl sulfatase, ammoniamono-ogygenase, carbonyl reductase, lipase, lipolase,mono-methanoxigenase, and mixtures thereof.

In still another aspect of the invention, a mixture of a lipophilicfluid and a fabric care agent containing functional moieties which arehydroxyl and aldehyde groups, are exposed to an oxidizing agents suchthat these functional moieties undergo oxidation, thereby transformingthe contaminant to a modified form, which can be one or more lowermolecular weight species and/or more polar species, compared to theoriginal form of the contaminant. The modified contaminant becomes lesscompatible with the lipophilic fluid and can be more easily separatedfrom the lipophilic fluid in the separation step. The transformation ofthe functional moieties is illustrated schematically below:

Oxidizing agents suitable for use herein include, but are not limitedto, potassium permanganate, ruthenium tetroxide, pyridiniumchlorochromate; and the like.

In still another aspect of the invention, a mixture of a lipophilicfluid and a fabric care agent containing functional moieties which areprotected hydroxyl groups, are exposed to radiation energy such thatthese functional moieties undergo homo- and/or heterolytic cleavage,thereby transforming the contaminant to a modified form, which can beone or more lower molecular weight species and/or more polar species,compared to the original form of the contaminant. The modifiedcontaminant becomes less compatible with the lipophilic fluid and can bemore easily separated from the lipophilic fluid in the separation step.The transformation of the functional moieties is illustratedschematically below:

In still another aspect of the invention, a mixture of a lipophilicfluid and a fabric care agent containing functional moieties which arecarboxylic acid groups, hydrogen phosphate ester, are exposed to a basesuch that these functional moieties undergo neutralization, therebytransforming the contaminant to a modified form, which can be one ormore lower molecular weight species and/or more polar species, comparedto the original form of the contaminant. The modified contaminantbecomes less compatible with the lipophilic fluid and can be more easilyseparated from the lipophilic fluid in the separation step. Thetransformation of the functional moieties is illustrated schematicallybelow:

Exemplary bases suitable for use herein include, but are not limited to,bicarbonate and carbonate salts of alkali and alkaline earth metals,hydroxy, and alkoxide salts of alkali and alkaline earth metals,tertiary amines and polyamines.

In still another aspect of the invention, a mixture of a lipophilicfluid and a fabric care agent containing functional moieties which areamino groups are exposed to a neutralizing, alkylating agent, such thatthese functional moieties undergo quaternization reactions, therebytransforming the contaminant to a modified form, which can be one ormore lower molecular weight species and/or more polar species, comparedto the original form of the contaminant. The modified contaminantbecomes less compatible with the lipophilic fluid and can be more easilyseparated from the lipophilic fluid in the separation step. Thetransformation of the functional moieties is illustrated schematicallybelow:

Exemplary neutralizing agents suitable for use herein include, but arenot limited to, mineral acids and organic acids. Alkylating agentssuitable for use herein include, but are not limited to, alkyl halides,dimethyl or other dialkyl sulfate.

In yet another aspect of the invention, a mixture of a lipophilic fluidand a fabric care agent containing functional moieties such as alkenyls,aromatic, amide, ester, vinyl chloride, epoxy and various silicone bond,such as Si—O—, Si—O—Si, Si-halogen, (as found in the followingcompounds: siloxanes, silanols, halosilanes, organoalkoxysilanes,organoaminosilanes, hydrosilanes) that undergo polymerization. Anexample is where a material containing unsaturated carbon bonds isexposed to an initiator (such as a catalyst) and/or energy (such asultraviolet light, heat, etc.) such that these functional moietiesundergo polymerization, thereby transforming the contaminant to amodified form, which can be one or more higher molecular weight species,compared to the original form of the contaminant. The modifiedcontaminant becomes less compatible with the lipophilic fluid and can bemore easily separated from the lipophilic fluid in the separation step.The transformation of the functional moieties is illustratedschematically below in the polymerization of ethylene:

Exemplary catalysts suitable for use herein include, but are not limitedto,organic and inorganic transition metal complexes, inorganic andorganic radical catalysts, organic and inorganic acids and bases, water,ultraviolet light, heat, and combinations thereof.

In an additional aspect of the invention, biological agents can be addedto the mixture of a lipophilic fluid and a fabric care agent such thatthe contaminant are transformed to a modified form, which can be one ormore lower molecular weight species and/or more polar species, comparedto the original form of the contaminant. The modified contaminantbecomes less compatible with the lipophilic fluid and can be more easilyseparated from the lipophilic fluid in the separation step.

Biological agents include, but are not limited to, bacteria, yeasts,molds, fungi, protozoa that are commonly used in oil spill clean-up.These biological agents are non-selective and are capable of digestinglinkages between C, O, and N atoms.

Modification of the Mixture with Purification Agents

In one aspect of the invention, the purification agents can be ionicstrength modifiers, such as the mono-valent alkaline metal cations, orthe di-valent alkaline earth metal cations or the di- or multi-valenttransitional metal cations. Nonlimiting examples include cations of Na;K; Li; Cs; Zn; Mg; Mn; Ni; Ba; Fe; La; Ce; Zr; Ca; Ce; Al; Cu; Fe; intheir cationically charged form, in their magnetizable form; andmixtures thereof.

The purification agents can also comprise unsubstittued or substitutedammonium cations, such as NH₄ ⁺ and quaternary ammonium cations.Quaternary ammonium surfactants are described in the art. The propertiesof these surfactants are very strongly influenced by the type ofsubstituent they contain. Chain length, degree of saturation, branchingor the presence and number of hydroxylic or ethoxy groups are some ofthe factors determining the properties of the surfactant. Whereastypical textile-conditioning actions are performed by cationicsurfactants with two long alkyl chains, cationic surfactants with onlyone long alkyl chain have been reported to improve the detergencyperformance in laundry detergents. Nonlimiting examples of quaternaryammonium compounds suitable for use herein as the purification agentsare disclosed in U.S. Pat. No. 3,123,640 and U.S. Pat. No. 3,141,905,both of which describe cation-active surface-active chemical compounds.The cation-active compounds are quaternary ammonium compounds derivedfrom lower monoalkyl dialkanolamines. The cation-active compounds alsoinclude a) dialiphatic, dialkoxylated quaternary ammonium compounds, andb) monoaliphatic, trialkoxylated quaternary ammonium compounds, asdescribed by formulae in the patents, and are useful in the practice ofthe invention as the polyoxyalkylene ammonium cationic surfactants.Additional exmples include but are not limited to decyltrimethylammonium compounds, octyldihydroxyethylmethyl ammonium compounds, andthe like.

These cations may be applied to the contaminated solvents or mixtures intheir salt form, which contain anionic species of hadiles (F⁻, Cl⁻, Br⁻,I⁻), hydroxide (OH⁻), carboxylates (CO₃ ⁻), sulfates (SO₄ ⁻), sulfites(SO₃ ⁻), nitrates (NO₃ ⁻), nitrites (NO₂ ⁻), phosphates (PO₄ ⁻), andmixtures thereof.

The purification agents based on metal cations, NH₄ ⁺; quaternaryammonium cations, and mixtures thereof, are typically prepared as asolution in a carrier solvent at a concentration of about 0.1 to about 1wt % of the carrier solvent. The carrier solvent is a solvent capable ofallowing for the cation to dissociate from its salt form. Nonlimitingexamples of carrier solvent include water or pH adjusted water. Thesecationic agents typically interact with the anionic species in thecontaminants; the resulting compounds can be easily precipitated out ofand separated from the dry cleaning solvent by convention techniques,such as filtration, centrifugation, decantation, and combinationsthereof.

By exposing the collected precipitants to a low pH (about 2-4) medium,the precipitants can be dissolved into the cationic agents and theanionic contaminants. The cationic agents can be reclaimed by passingthe solution containing the dissolved precipitants through a cationexchange column.

Alternatively, a magnetic field can be applied to draw the precipitantsout of the dry cleaning solvent, since some of the metal cations may bein a magnetizable form. Once the precipitants have been removed from thedry cleaning solvent, the magnetic field can be reversed, to release theprecipitants into a low pH medium, and the cationic agents can beregenerated and recycled as described above.

The ability to recycled or regenerated the cationic agents provide agreat advantage since no additional materials needing disposal isgenerated by the solvent purification method of the present invention.

In another aspect of the present invention, the purification agents maybe pH modifiers selected from mineral acids or organic acids. Mineralacids include, bur are not limited to, HCl, HBr, HI, sulfuric acid,sulfonic acid, nitric acid, phosphoric acid, carboxylic acid. These pHmodifiers may have one, two or three dissociable protons. Organic acidsrefer to the above mineral acids having replaced one or more of theprotons with linear, branched or cyclic, saturated or unsaturated alkylgroups.

In still another aspect of the invention, the purification agent may bean aggregation agent such as, water or polymers. For example, water iswell-known to induce formation of surfactant aggregates in non-polarsolvents that may contain two or more surfactant molecule per aggregate.Thus, the aggregates may become large enough to be separated from themixture more easily by the separation techniques disclosed herein. Theaggregation agents include, but are not limited to, cationic or anionicpolymers such as diallyl dimethyl, flocculants such as poly(ethyleneoxide), poly(methacrylate) and poly(acrylic acid).

Addition of aggregation agent may be combined with a treatment such asagitation (mixing) and/or sonication to disperse aggregation agent andto provide mechanical energy to induce contaminant molecules to condenseinto aggregates.

In yet another aspect of the present invention, the purification agentmay be a gelling agent such as sorbitol gelators, metal fatty estersoaps, calcium silicates and treated calcium silicates, organicderivatives of castor oil, cellulose derivatives, lecithin, xanthum gum,alginate, and mixtures thereof.

A class of sorbitol derivatives can be used as gelling agents in thepresent invention. For example, 1,2:2,4-di-O-benzylidene-D-sorbitol(DBS) can form aggregated structures, via hydrogen bonding, in a widevariety of organic solvents, including the lipophilic solvents usedherein. Adding the sorbitol gelators to the mixture can result in theformation of aggregates between the sorbitol gelators and contaminantscapable of forming hydrogen bonding. The resulting aggregates can beseparated from the lipophilic fluids easily.

Metal ester soaps can be used as the gelling agents to furtherfacilitate the separation of the contaminants from the lipophilic fluid.Metal ester soaps comprise a metal ion, such as aluminum, magnesium,zinc, and lithium, and an ester having the general formula: R(CO)O—,wherein the R can be saturated or unsaturated, linear, branched orcyclic C1-C30 alkyl chains. For example, suitable metal fatty esters maycomprise metal ions selected from aluminum, magnesium, zinc or lithium,and the fatty acid ester having a chain length of 10 to 28 carbon atoms,or of 12 to 22 carbon atoms, such as stearates, behenates, laurates andpalmitates. The aluminum/magnesium hydroxide stearate is commerciallyavailable from Giulini Corporation, Bound Brook, N.J., under the generalname of Gilugel®.

It is understood that the cations in the metal ester soap can alsofunction as the ionic strength modifiers.

Calcium silicates and treated calcium silicates can also be used as thegelling agent in the present invention. Common forms of calciumsilicates include CaSiO₃, CaSiO₄(OH)₂, CaSiO₅(OH)₄. The calciumsilicates can be treated with a wide variety of nonpolar organiccompounds to render the materials more hydrophobic and less reactive.Useful calcium silicates that are commercially available include thefollowing: Hubersorb® (Huber Corp., Harve de Grace, Md.), and Micro-Cel®(Celite Corp., Denver, Co.). Other silicates such as magnesium silicate,or magnesium/aluminum silicate are also useful herein.

Also suitable for use herein as the gelling agent are various organicderivatives of castor oil, such as Thixcin® R, Thixatrol® ST, and thelike. The principal constituent of these castor oil derivative isglyceryl tris-12-hydroxystearate. Various inorganic derivatives ofcastor oil are also useful herein, such as Thixcin® GR, Thixatrol® GST,Thixseal® 1084, and the like. All these castor oil derivatives ormixtures thereof are available from Rheox, Inc., Hightstown, N.J.

Exemplary cellulose derivatives useful as gelling agents in the presentinvention include cellulose acetate, cetyl hydroxy ethyl cellulose andother modified celluloses.

Other suitable gelling agents may be derived from natural sources, suchas xanthum gum, lecithin, alginate, and the like.

A liquid immiscible with the lipophilic fluid can be used as the liquidextraction agent. A liquid extraction agent, such as an immiscibleliquid, can be added to the mixture to provide a second phase, and thecontaminant(s) can preferentially migrate from the lipophilic fluid orthe mixture to the the second phase or the immiscible liquid. Thedriving force is based on the partition coefficient of thecontaminant(s) in the respective liquids.

Extracting fluids capable of creating a second phase from the lipophilicfluid are suitable for use herein. Nonlimiting examples of liquidextracting agents include, but are not limited to, of water; linear orbranched, cyclic, acyclic or aromatic alcohols; linear or branched,cyclic, acyclic or aromatic diols; and mixtures thereof.

Separation Techniques

After the modification, the modified contaminants can be separated fromthe solvent and/or composition using several well known techniques, suchas precipitation; sedimentation; centrifugation; decantation;particulate filtration; membrane filtration; exposure to an absorbent,an adsorbent, a photocatalyst, or mixtures thereof; magnetic separation;temperature modification; liquid-liquid extraction; and combinationsthereof.

The modified contaminants that become insoluble in the solvent can beseparated from the dry cleaning solvent or composition by density-and/or gravity-based techniques, such as precipitation, sedimentation,decantation, centrifugation.

Precipitation is initiated by a phase separation, which leads to theformation of a solid. Subsequently, gravity separates the solid from thebulk solvent in a 1 to 48 hour time period. Additionally, the formationof a precipitate causes an optical change in the bulk solvent, such thatthe bulk solvent becomes hazy or cloudy.

Sedimentation is the separation of suspended solid particles from aliquid stream via gravitational settling. Sedimentation can also be usedto separate solid particles based on differences in their settlingrates.

“Decantation” and “density gradation” are gravity-type separationmethods. A “decanter” is defined as a vessel used to separate a streamcontinuously into two liquid phases using the force of gravity. UsingStokes' law, one can derive the settling velocity of the droplets in thecontinuous phase and design a decanter accordingly.

Centrifugation is a technique that separates materials based upondifferences in density, the rate of separation being amplified byapplying increasing rotational force. The force is called a centrifugalforce and the apparatus providing the rotational force is called acentrifuge. Centrifugation can be used in combination with precipitationor sedimentation to enhance and accelerate the separation.

When the purification agents contain cationic agents based on thealkaline earth metal cations or transitional metal cations, or in theirmagnetizable form, magnetization can be used to remove the modifiedcontaminants (i.e., precipitants) from the solvent.

Additionally, temperature modification, such as lowering the temperatureof the mixture, can further enhance the separation of the contaminantsfrom the mixture. For example, the compatibility or solubility of thecontaminants in the solvent or mixture can be reduced with loweringtemperature. In another example, the contaminants may undergo phasechange (such as crystallization) and precipitate out of the solvent ormixture.

Particulate filtration can be used for the removal of solidparticulates, aggregates, or precipitants from liquids. For example,liquids with low solids content can be filtered such that they becomeoptically clear liquids. The cartridges are typically cylindrical inconfiguration, though other shapes are also acceptable. The filterermedia inside the cartridge can be either pleated or non-pleated,disposable or cleanable/regenerable. The filter media is usuallysupported by and/or integrally bonded to plastic or metal hardware.

Membrane filtration encompasses the transfer of solute through amembrane or the transfer of solvent through a membrane, as a drivingforce across the membrane. Dialysis and osmosis are embodiments ofmembrane filtration techniques. In contrast to particulate filtration,membrane filtration is effective in the removal of low molecular weightsolute molecules or ions from a solution by passing them through amembrane driven by a concentration gradient, and optionally, a pressuregradient, across the membrane.

Membranes suitable for use herein may comprise porous inorganicmaterials, such as alumina, zirconia, titania, silicium carbide, andmixtures thereof. Membranes suitable for use herein may also compriseorganic materials such as polytetrafluoroethylene; poly(vinylidenefluoride); polypropylene; polyethylene; cellulose esters; polycarbonate;polysulfone/poly(ether sulfone); polyimide/poly(ether imide); aliphaticpolyamide; polyetheretherketone; cross linked polyalkylsiloxane; andmixtures thereof. Suitable membranes are commercially available from GEAFiltration, or GE Osmonics Inc., Minnetoka, Minn.

In one embodiment where low molecular weight solutes are retained on orin the membrane, rather than passing through the membrane; the solutescan be washed out with solvents or water by exchanging salts and othermicrospecies with the solute molecules. Thus, membrane can beregenerated. Repeated or continuous addition of fresh solvent flushesout the low molecular weight solutes efficiently and rapidly.

Extraction is the selective transfer of a compound or compounds from oneliquid to another immiscible liquid or from a solid to a liquid. Theformer process is called a liquid-liquid extraction, wherein a foreignsubstance, such as an immiscible liquid, is introduced to provide asecond phase, to which the compound(s) can preferentially migrate. Thedriving force is based on the partition coefficient of the solutecompound(s) in the respective liquids. In this separation technique, thecompounds in the two liquid phases are merely separated by an interface(i.e., a chemical barrier), not by a physical barrier.

Extracting fluids suitable for use herein to create a second phase fromthe dry cleaning solvents include, but are not limited to, of water;linear or branched, cyclic or acyclic alcohols; linear or branched,cyclic or acyclic diols; and mixtures thereof.

The modified contaminants can also be removed from the dry cleaningsolvent or composition by contacting the mixture with an absorbentmaterial, an adsorbent material, a photocatalyst, or mixtures thereof.These materials can be added to the mixture as solidparticulates/powders or can be contained in a cartridge or likecontainer.

Suitable adsorbent materials include, but are not limited to, activatedcarbon, clay, polar agents, apolar agents, charged agents, zeolites,nanoparticles, and mixtures thereof.

The polar agent suitable for use herein as the adsorbent material hasthe formula:(Y_(a)—O_(b))Xwherein Y is Si, Al, Ti, P; a is an integer from about 1 to about 5; bis an integer from about 1 to about 10; and X is a metal. In oneembodiment, the polar agent suitable for use herein as the adsorbentmaterial is selected from the group consisting of: silica, diatomaceousearth, aluminosilicates, polyamide resin, alumina, zeolites and mixturesthereof. In one embodiment, the polar agent is silica, more specificallysilica gel. Suitable polar agents include Silfam® silica gel, availablefrom Nippon Chemical Industries Co., Tokyo, Japan; and Davisil® 646silica gel, available from W. R. Grace, Columbia, Md.

Apolar agents suitable for use herein as the adsorbent material compriseone or more of the following: polystyrene, polyethylene, and/or divinylbenzene. The apolar agent may be in the form of a fibrous structure,such as a woven or nonwoven web. Suitable apolar agents includeAmberlite® XAD-16 and XAD-4, available from Rohm & Haas, Philadelphia,Pa.

The charged agents suitable for use herein are selected from the groupconsisting of: anionic materials, cationic materials, zwitterionicmaterials and mixtures thereof. In one embodiment, the charged agent hasthe formula:(W-Z)Twherein W is Si, Al, Ti, P, or a polymer backbone; Z is a chargedsubstituent group and T is a counterion selected from alkaline, alkalineearth metals and mixtures thereof. For example, T may be: sodium,potassium, ammonium, alkylammonium derivatives, hydrogen ion; chloride,hydroxide, fluoride, iodide, carboxylate, etc. The W portion typicallycomprises from about 1% to about 15% by weight of the charged agent. Thepolymer backbone typically comprises a material selected from the groupconsisting of: polystryrene, polyethylene, polydivinyl benzene,polyacrylic acid, polyacrylamide, polysaccharide, polyvinyl alcohol,copolymers of these and mixtures thereof. The charged substituenttypically comprises sulfonates, phosphates, quaternary ammonium saltsand mixtures thereof. The charged substituent may comprise alcohols;diols; salts of carboxylates; salts of primary and secondary amines andmixtures thereof. Suitable charged agents are available from Rohm &Haas, Philadelphi, Pa., under the designation IRC-50.

Suitable absorbent materials include, but are not limited to,hydrogel-forming absorbent materials or absorbent gelling material(AGM), and mixtures thereof.

Hydrogel-forming absorbent polymers are also commonly referred to as“hydrocolloids” and can include polysaccharides, such as carboxymethylstarch, carboxymethyl cellulose, and hydroxypropyl cellulose; nonionictypes such as polyvinyl alcohol, and polyvinyl ethers; cationic typessuch as polyvinyl pyridine, polyvinyl morpholinione, andN,N-dimethylaminoethyl or N,N-diethylaminopropyl acrylates andmethacrylates, and the respective quaternary salts thereof. Thecopolymers thereof may be partially neutralized, slightly networkcrosslinked, or both. Typically, hydrogel-forming absorbent polymershave a multiplicity of anionic or cationic functional groups. Thesepolymers can be used either alone or in mixtures of two or moredifferent polymers. Examples of these polymer materials are disclosed inU.S. Pat. Nos. 3,661,875; 4,076,663; 4,093,776; 4,666,983, and4,734,478.

Other hydrogel forming materials are also suitable for use herein as theabsorbent materials. Nonlimiting examples of these gels suitable for useherein may be based on acrylamides, acrylates, acrylonitriles,diallylammonium chloride, dialkylammonium chloride, and other monomers.Some suitable gels are disclosed in U.S. Pat. Nos. 4,555,344, 4,828,710,and European Application EP 648,521 A2.

The hydrogel-forming polymer component may also be in the form of amixed-bed ion-exchange composition comprising a cation-exchangehydrogel-forming absorbent polymer and an anion-exchangehydrogel-forming absorbent polymer. Such mixed-bed ion-exchangecompositions are described in, e.g., U.S. patent application Ser. No.09/130,321, filed Jan. 7, 1998 by Ashraf, et al. (P&G Case 6976R); andU.S. Pat. No. 6,121,509.

Suitable photocatalysts include, but are not limited to semiconductorphotocatalysts, comprising a transition metal atom exchanged into theframework of a zeolite and/or a mesoporous molecular sieve material,which are subsequently loaded with a photoactive material, such astitanium dioxide. Such semiconductor photocatalysts are described inU.S. Pat. No. 6,585,863.

The Cleaning System and Apparatus

The present invention also includes a cleaning system and apparatussuitable for use in the method described above. The cleaning systemcomprises a fabric article treating vessel, a dry cleaning solventreservoir, and optionally, a sensor for monitoring the contaminant levelin the dry cleaning solvent. When contaminant concentration exceeds somepre-determined value, it would indicate that the dry cleaning solventhas reached maximum contaminant holding tolerance and needs to bepurified. Additionally, solvent purification/recovery device comprisinga modification unit capable of conducting the purification method of thepresent invention may also be provided as an integral part of thesystem/apparatus. However, it needs not be. The solventpurification/recovery unit can be a stand-alone device, separate fromthe dry cleaning system.

Any suitable fabric article treating vessel known to those of ordinaryskill in the art can be used. The fabric article treating vesselreceives and retains a fabric article to be treated during the operationof the cleaning system. In other words, the fabric article treatingvessel retains the fabric article while the fabric article is beingcontacted by the dry cleaning solvent. Nonlimiting examples of suitablefabric article treating vessels include commercial cleaning machines,domestic, in-home, washing machines, and clothes drying machines.

The methods and systems of the present invention may be used in aservice, such as a cleaning service, diaper service, uniform cleaningservice, or commercial business, such as a Laundromat, dry cleaner,linen service which is part of a hotel, restaurant, convention center,airport, cruise ship, port facility, casino, or may be used in the home.

The methods of the present invention may be performed in an apparatusthat is a modified existing apparatus and is retrofitted in such amanner as to conduct the method of the present invention in addition torelated methods.

The methods of the present invention may also be performed in anapparatus that is specifically built for conducting the presentinvention and related methods.

Further, the methods of the present invention may be added to anotherapparatus as part of a dry cleaning solvent processing system. Thiswould include all the associated plumbing, such as connection to achemical and water supply, and sewerage for waste wash fluids.

The methods of the present invention may also be performed in anapparatus capable of “dual mode” functions. A “dual mode” apparatus isone capable of both washing and drying fabrics within the same vessel(i.e., drum). Dual mode apparatuses for aqueous laundry processes arecommercially available, particularly in Europe. Additionally, the methodof the present invention may also be performed in an apparatus capableof performing “bi-modal” cleaning functions. A “bi-modal” apparatus isone capable of performing both non-aqueous washing and aqueous washingin the same vessel, wherein the two washing modes can be performed insequential washing cycles or in a combination washing cycle.Additionally, the bi-modal machine is capable of fully drying theclothes without having to transfer them to a separate machine. That is,a machine can have the bi-modal function as well as the dual-modefunction.

An apparatus suitable for use in the present invention will typicallycontain some type of control systems, including electrical systems, suchas “smart control systems”, as well as more traditionalelectro-mechanical systems. The control systems would enable the user toselect the size of the fabric load to be cleaned, the type of soiling,the extent of the soiling, the time for the cleaning cycle.Alternatively, the control systems provide for pre-set cleaning and/orrefreshing cycles, or for controlling the length of the cycle, based onany number of ascertainable parameters the user programmed into theapparatus. For example, when the collection rate of dry cleaning solventreaches a steady rate, the apparatus could turn its self off after afixed period of time, or initiate another cycle for the dry cleaningsolvent.

In the case of electrical control systems, one option is to make thecontrol device a so-called “smart device”, which provides smartfunctions, such as self diagnostics; load type and cycle selection;Internet links, which allow the user to start the apparatus remotely,inform the user when the apparatus has cleaned a fabric article, orallow the supplier to remotely diagnose problems if the apparatusmalfunctioned. Furthermore, the apparatus of the present invention canalso be a part of a cleaning system, the so called “smart system”, inwhich the present apparatus has the capability to communicate withanother laundry apparatus that performs a complimentary operation (suchas a washing machine or a dryer) to complete the remainder of thecleaning process.

While particular embodiments of the present invention have beenillustrated and described, it would be apparent to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

All percentages stated herein are by weight unless otherwise specified.It should be understood that every maximum numerical limitation giventhroughout this specification will include every lower numericallimitation, as if such lower numerical limitations were expresslywritten herein. Every minimum numerical limitation given throughout thisspecification will include every higher numerical limitation, as if suchhigher numerical limitations were expressly written herein. Everynumerical range given throughout this specification will include everynarrower numerical range that falls within such broader numerical range,as if such narrower numerical ranges were all expressly written herein.

All documents cited are, in relevant part, incorporated herein byreference; the citation of any document is not to be construed as anadmission that it is prior art with respect to the present invention.

1. A process for purifying a lipophilic fluid, the process comprising the steps of: (a) obtaining a mixture comprising a lipophilic fluid and one or more contaminants; (b) chemically modifying the contaminant by oxidation; (c) contacting the mixture with a purification agent comprising an ionic strength modifier selected from the group consisting of alkali metal cations, alkaline earth metal cations, transition metal cations, ammonium cations and substituted ammonium cations, said ionic strength modifier being in solution in water, thereby changing the solubility of the contaminant in the mixture; and (d) separating the contaminant from the lipophilic fluid by precipitation.
 2. The process of claim 1 wherein contaminant has a functional moiety selected from the group consisting of acetals, ketals, orthoesters, amides, imides, esters, carbonates, ester-quaternary nitrogen, alkenyls, hydroxyls, aldehydes, protected hydroxyls, carboxylic acids, hydrogen phosphate esters, ethers, amines, Si—O—, Si—O—Si, Si-halogen, and mixtures thereof.
 3. The process of claim 1 wherein the chemical modification step (b) is an oxidation reaction selected from the group consisting of ozonolysis dihydroxylation, expoxidation, Walker reaction and oxidative cleavage.
 4. The process of claim 1 wherein the contaminant is a polymer having one or more functional moieties located in the polymer chain backbone and/or in the polymer chain end.
 5. The process of claim 4 wherein the functional moiety is selected from the group consisting of acetals, ketals, orthoesters, amides, imides, esters, carbonates, ester-quaternary nitrogen, alkenyls, hydroxyls, aldehydes, protected hydroxyls, carboxylic acids, hydrogen phosphate esters, ethers, amines, Si—O—, Si—O—Si, Si-halogen, and mixtures thereof.
 6. The process of claim 1 wherein the contaminant is selected from the group consisting of fabric treating agents, laundry soils, and mixtures thereof.
 7. The process of claim 6 wherein the contaminant is a fabric treating agent selected from the group consisting of soil release polymers, detersive surfactants, bleaches, enzymes, perfumes, softening agents, finishing polymers, dyes, dye transfer inhibiting agents, dye fixatives, fiber rebuild agents, wrinkle reducing and/or removing agents, fiber repair agents, perfume release and/or delivery agents, shape retention agents, fabric and/or soil targeting agents, antibacterial agents, anti-discoloring agents, hydrophobic finishing agents, UV blockers, brighteners, pigments, pill prevention agents, temperature control agent, skin care lotions, humectants, moisturizers, viscosity modifiers, insect repellents, fire retardants, and mixtures thereof.
 8. The process of claim 1 wherein the lipophilic fluid is selected from the group consisting of linear or cyclic siloxanes, glycol ethers, glycerine ethers, hydrocarbons, fluorocarbons, chlorocarbons, and mixtures thereof.
 9. The process of claim 1 wherein the lipophilic fluid comprises decamethylcyclopentasiloxane. 